| msg104217 - (view) |
Author: Matthias Klose (doko) *  |
Date: 2010-04-26 11:00 |
| Building with -flto (GCC 4.5.0) requires passing the very same optimization flags to the linker (lto1) as well. The attached patch just does this. Tested on Linux only, I don't know what will/could break on on other systems/compilers. Tested with a static build (--disable-shared) on x86_64. pybench results improve by 5% when building with 4.5.0 instead of 4.4.3, and by another 5% by building with -flto. |
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| msg104221 - (view) |
Author: Marc-Andre Lemburg (lemburg) * |
Date: 2010-04-26 11:22 |
| Matthias Klose wrote: > > New submission from Matthias Klose <doko@debian.org>: > > Building with -flto (GCC 4.5.0) requires passing the very same optimization flags to the linker (lto1) as well. The attached patch just does this. Tested on Linux only, I don't know what will/could break on on other systems/compilers. On some systems, this may very well break, due to configruations where LDFLAGS and CFLAGS contain the same options. While this is normally not much of a problem, some compilers may complain about this. E.g. GCC on Mac OS X complains about duplicate use of the -sysroot option. It's probably better to just pass OPT to the linker instead. |
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| msg104222 - (view) |
Author: Matthias Klose (doko) * |
Date: 2010-04-26 11:27 |
| > It's probably better to just pass OPT to the linker instead. not enough, because -fno-strict-aliasing might be passed in BASE_CFLAGS. |
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| msg104466 - (view) |
Author: Roumen Petrov (rpetrov) * |
Date: 2010-04-28 21:46 |
| LDSHARED not always is compiler and I'm not sure that linkers always accept compiler flags . After fix of issue xxx about CFLAGS and issues a, b, c, for LDFLAGS now all is passed to python build system and users could set argument to both variables : CFLAGS and LDFLAGS . |
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| msg104505 - (view) |
Author: Marc-Andre Lemburg (lemburg) * |
Date: 2010-04-29 13:42 |
| Matthias Klose wrote: > > Matthias Klose <doko@debian.org> added the comment: > >> It's probably better to just pass OPT to the linker instead. > > not enough, because -fno-strict-aliasing might be passed in BASE_CFLAGS. Shouldn't -fno-strict-aliasing be added to OPT instead of BASE_CFLAGS ? After all, it's an optimization settings. |
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| msg104520 - (view) |
Author: Matthias Klose (doko) * |
Date: 2010-04-29 15:20 |
| my understanding is that the builder is allowed to overwrite OPT, but not BASE_CFLAGS. |
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| msg104865 - (view) |
Author: Marc-Andre Lemburg (lemburg) * |
Date: 2010-05-03 18:11 |
| Matthias Klose wrote: > > Matthias Klose <doko@debian.org> added the comment: > > my understanding is that the builder is allowed to overwrite OPT, but not BASECFLAGS. The builder should actually be allowed to override the complete CFLAGS and LDFLAGS settings, but for historic reasons, this is currently not possible and you're right: OPT was meant to be overridden by the user and BASECFLAGS is reserved for configure use. Since just adding the CFLAGS to the linker invokation breaks on various platforms (the linker doesn't expect compiler flags or complains due to duplicate flags), this simple route will not work. I suppose the best way to do this is by adding an extra check to configure.in that tests whether the new GCC 4.5 option is supported and also check whether CFLAGS can be passed to the linker. If this test succeed, the configure script could then add CFLAGS to the linker invokations or perhaps merge CFLAGS into LDFLAGS. |
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| msg220445 - (view) |
Author: Mark Lawrence (BreamoreBoy) * |
Date: 2014-06-13 14:39 |
| Is this still relevant as GCC 4.9.0 was released on April 22, 2014? |
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| msg380479 - (view) |
Author: Irit Katriel (iritkatriel) * |
Date: 2020-11-06 22:23 |
| I think this was resolved by . |
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